drm/i915/guc: Enable Wa_22011802037 for gen12 GuC based platforms

Initiating a reset when the command streamer is not idle or in the
middle of executing an MI_FORCE_WAKE can result in a hang. Multiple
command streamers can be part of a single reset domain, so resetting one
would mean resetting all command streamers in that domain.

To workaround this, before initiating a reset, ensure that all command
streamers within that reset domain are either IDLE or are not executing
a MI_FORCE_WAKE.

Enable GuC PRE_PARSER WA bit so that GuC follows the WA sequence when
initiating engine-resets.

For gt-resets, ensure that i915 applies the WA sequence.

Opens to address in future patches:
- The part of the WA to wait for pending forcewakes is also applicable
  to execlists backend.
- The WA also needs to be applied for gen11
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220415224025.3693037-3-umesh.nerlige.ramappa@intel.com

drivers/gpu/drm/i915/gt/intel_gt_pm.c

@@ -181,15 +181,16 @@ static void gt_sanitize(struct intel_gt *gt, bool force)
 	if (intel_gt_is_wedged(gt))
 		intel_gt_unset_wedged(gt);
 
-	for_each_engine(engine, gt, id)
+	/* For GuC mode, ensure submission is disabled before stopping ring */
+	intel_uc_reset_prepare(&gt->uc);
+
+	for_each_engine(engine, gt, id) {
 		if (engine->reset.prepare)
 			engine->reset.prepare(engine);
 
-	intel_uc_reset_prepare(&gt->uc);
-
-	for_each_engine(engine, gt, id)
 		if (engine->sanitize)
 			engine->sanitize(engine);
+	}
 
 	if (reset_engines(gt) || force) {
 		for_each_engine(engine, gt, id)

drivers/gpu/drm/i915/gt/intel_gt_regs.h

@@ -841,6 +841,24 @@
 #define   CTC_SHIFT_PARAMETER_SHIFT		1
 #define   CTC_SHIFT_PARAMETER_MASK		(0x3 << CTC_SHIFT_PARAMETER_SHIFT)
 
+/* GPM MSG_IDLE */
+#define MSG_IDLE_CS		_MMIO(0x8000)
+#define MSG_IDLE_VCS0		_MMIO(0x8004)
+#define MSG_IDLE_VCS1		_MMIO(0x8008)
+#define MSG_IDLE_BCS		_MMIO(0x800C)
+#define MSG_IDLE_VECS0		_MMIO(0x8010)
+#define MSG_IDLE_VCS2		_MMIO(0x80C0)
+#define MSG_IDLE_VCS3		_MMIO(0x80C4)
+#define MSG_IDLE_VCS4		_MMIO(0x80C8)
+#define MSG_IDLE_VCS5		_MMIO(0x80CC)
+#define MSG_IDLE_VCS6		_MMIO(0x80D0)
+#define MSG_IDLE_VCS7		_MMIO(0x80D4)
+#define MSG_IDLE_VECS1		_MMIO(0x80D8)
+#define MSG_IDLE_VECS2		_MMIO(0x80DC)
+#define MSG_IDLE_VECS3		_MMIO(0x80E0)
+#define  MSG_IDLE_FW_MASK	REG_GENMASK(13, 9)
+#define  MSG_IDLE_FW_SHIFT	9
+
 #define FORCEWAKE_MEDIA_GEN9			_MMIO(0xa270)
 #define FORCEWAKE_RENDER_GEN9			_MMIO(0xa278)
 

drivers/gpu/drm/i915/gt/intel_reset.c

@@ -771,14 +771,15 @@ static intel_engine_mask_t reset_prepare(struct intel_gt *gt)
 	intel_engine_mask_t awake = 0;
 	enum intel_engine_id id;
 
+	/* For GuC mode, ensure submission is disabled before stopping ring */
+	intel_uc_reset_prepare(&gt->uc);
+
 	for_each_engine(engine, gt, id) {
 		if (intel_engine_pm_get_if_awake(engine))
 			awake |= engine->mask;
 		reset_prepare_engine(engine);
 	}
 
-	intel_uc_reset_prepare(&gt->uc);
-
 	return awake;
 }
 

drivers/gpu/drm/i915/gt/uc/intel_guc.c

@@ -292,6 +292,10 @@ static u32 guc_ctl_wa_flags(struct intel_guc *guc)
 	    GRAPHICS_VER_FULL(gt->i915) < IP_VER(12, 50))
 		flags |= GUC_WA_POLLCS;
 
+	/* Wa_22011802037: graphics version 12 */
+	if (GRAPHICS_VER(gt->i915) == 12)
+		flags |= GUC_WA_PRE_PARSER;
+
 	return flags;
 }
 

drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h

@@ -98,6 +98,7 @@
 #define   GUC_LOG_BUF_ADDR_SHIFT	12
 
 #define GUC_CTL_WA			1
+#define   GUC_WA_PRE_PARSER		BIT(14)
 #define   GUC_WA_POLLCS			BIT(18)
 
 #define GUC_CTL_FEATURE			2

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -1540,6 +1540,89 @@ static void guc_reset_state(struct intel_context *ce, u32 head, bool scrub)
 	lrc_update_regs(ce, engine, head);
 }
 
+static u32 __cs_pending_mi_force_wakes(struct intel_engine_cs *engine)
+{
+	static const i915_reg_t _reg[I915_NUM_ENGINES] = {
+		[RCS0] = MSG_IDLE_CS,
+		[BCS0] = MSG_IDLE_BCS,
+		[VCS0] = MSG_IDLE_VCS0,
+		[VCS1] = MSG_IDLE_VCS1,
+		[VCS2] = MSG_IDLE_VCS2,
+		[VCS3] = MSG_IDLE_VCS3,
+		[VCS4] = MSG_IDLE_VCS4,
+		[VCS5] = MSG_IDLE_VCS5,
+		[VCS6] = MSG_IDLE_VCS6,
+		[VCS7] = MSG_IDLE_VCS7,
+		[VECS0] = MSG_IDLE_VECS0,
+		[VECS1] = MSG_IDLE_VECS1,
+		[VECS2] = MSG_IDLE_VECS2,
+		[VECS3] = MSG_IDLE_VECS3,
+		[CCS0] = MSG_IDLE_CS,
+		[CCS1] = MSG_IDLE_CS,
+		[CCS2] = MSG_IDLE_CS,
+		[CCS3] = MSG_IDLE_CS,
+	};
+	u32 val;
+
+	if (!_reg[engine->id].reg)
+		return 0;
+
+	val = intel_uncore_read(engine->uncore, _reg[engine->id]);
+
+	/* bits[29:25] & bits[13:9] >> shift */
+	return (val & (val >> 16) & MSG_IDLE_FW_MASK) >> MSG_IDLE_FW_SHIFT;
+}
+
+static void __gpm_wait_for_fw_complete(struct intel_gt *gt, u32 fw_mask)
+{
+	int ret;
+
+	/* Ensure GPM receives fw up/down after CS is stopped */
+	udelay(1);
+
+	/* Wait for forcewake request to complete in GPM */
+	ret =  __intel_wait_for_register_fw(gt->uncore,
+					    GEN9_PWRGT_DOMAIN_STATUS,
+					    fw_mask, fw_mask, 5000, 0, NULL);
+
+	/* Ensure CS receives fw ack from GPM */
+	udelay(1);
+
+	if (ret)
+		GT_TRACE(gt, "Failed to complete pending forcewake %d\n", ret);
+}
+
+/*
+ * Wa_22011802037:gen12: In addition to stopping the cs, we need to wait for any
+ * pending MI_FORCE_WAKEUP requests that the CS has initiated to complete. The
+ * pending status is indicated by bits[13:9] (masked by bits[ 29:25]) in the
+ * MSG_IDLE register. There's one MSG_IDLE register per reset domain. Since we
+ * are concerned only with the gt reset here, we use a logical OR of pending
+ * forcewakeups from all reset domains and then wait for them to complete by
+ * querying PWRGT_DOMAIN_STATUS.
+ */
+static void guc_engine_reset_prepare(struct intel_engine_cs *engine)
+{
+	u32 fw_pending;
+
+	if (GRAPHICS_VER(engine->i915) != 12)
+		return;
+
+	/*
+	 * Wa_22011802037
+	 * TODO: Occasionally trying to stop the cs times out, but does not
+	 * adversely affect functionality. The timeout is set as a config
+	 * parameter that defaults to 100ms. Assuming that this timeout is
+	 * sufficient for any pending MI_FORCEWAKEs to complete, ignore the
+	 * timeout returned here until it is root caused.
+	 */
+	intel_engine_stop_cs(engine);
+
+	fw_pending = __cs_pending_mi_force_wakes(engine);
+	if (fw_pending)
+		__gpm_wait_for_fw_complete(engine->gt, fw_pending);
+}
+
 static void guc_reset_nop(struct intel_engine_cs *engine)
 {
 }
@@ -3795,7 +3878,7 @@ static void guc_default_vfuncs(struct intel_engine_cs *engine)
 
 	engine->sched_engine->schedule = i915_schedule;
 
-	engine->reset.prepare = guc_reset_nop;
+	engine->reset.prepare = guc_engine_reset_prepare;
 	engine->reset.rewind = guc_rewind_nop;
 	engine->reset.cancel = guc_reset_nop;
 	engine->reset.finish = guc_reset_nop;